Submission #451568

#	Time	Username	Problem	Language	Result	Execution time	Memory
451568		ACmachine	Candies (JOI18_candies)	C++17	100 / 100	727 ms	32812 KiB

candies

#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)

const double EPS = 1e-9;
const int MOD = 1e9+7;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {1, 0, -1, 0, -1, 1, 1, -1};
const vi dx = {0, 1, 0, -1, -1, 1, -1, 1};

void DBG(){cout << "]" << endl;}
template<typename T, typename ...U> void DBG(const T& head, const U... args){ cout << head << "; "; DBG(args...); }
#define dbg(...) cout << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__);
#define chk() cout << "Check at line(" << __LINE__ << ") hit." << endl;

template<class T, unsigned int U>
ostream& operator<<(ostream& out, const array<T, U> &v){out << "[";  REP(i, U) out << v[i] << ", ";  out << "]"; return out;}
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}

template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());


int main(){
 	ios_base::sync_with_stdio(false);
 	cin.tie(NULL); cout.tie(NULL);
    int n; cin >> n;
    vector<int> a(n);
    cin >> a;
    set<array<ll, 3>> intervals; // [l, r, change]
    set<array<ll, 3>> rev_intervals; // [change, r, l]
    vector<vector<ll>> ps(2, vector<ll>(n + 1, 0));

    REP(i, n){
        REP(j, 2){
            ps[j][i + 1] += ps[j][i];
        }
        ps[i%2][i + 1] += a[i];
    }
    REP(i, n){
        intervals.insert({i, i, a[i]});
        rev_intervals.insert({a[i], i, i});
    }
    ll ans = 0;
    REP(i, (n + 1) / 2){
        //dbg(intervals);
        auto it2 = *rev_intervals.rbegin();
        auto it = it2;
        swap(it[0], it[2]);
        /*
        ll nid = -1;
        REP(j, intervals.size()){
            if(intervals[j][0] < 0 || intervals[j][1] >= n)
                continue;
            if(nid == -1 || intervals[j][2] > intervals[nid][2])
                nid = j;
        }
         */
        ans += it[2];
        int nl = it[0] - 1;
        int nr = it[1] + 1;
        /*
        if(nid != 0 && intervals[nid - 1][1] == nl){
            nl = intervals[nid - 1][0];
        }
        if(nid != (int)intervals.size() - 1 && intervals[nid + 1][0] == nr){
            nr = intervals[nid + 1][1];
        }
         */
        auto pit = intervals.find(it);
        if(pit != intervals.begin()){
            pit--;
            if((*pit)[1] == nl) {
                nl = (*pit)[0];
                intervals.erase(pit);
                auto tm = (*pit);
                swap(tm[0], tm[2]);
                rev_intervals.erase(tm);
            }
        }
        auto nit = intervals.find(it);
        nit++;
        if(nit != intervals.end()){
            if((*nit)[0] == nr){
                nr = (*nit)[1];
                intervals.erase(nit);
                auto tm = (*nit);
                swap(tm[0], tm[2]);
                rev_intervals.erase(tm);
            }
        }
        ll nch;
        if(nl < 0 || nr >= n)
            nch = -INFF;
        else {
            nch = ps[nl % 2][nr + 1] - ps[nl % 2][nl];
            nch -= (ps[(nl + 1) % 2][nr + 1] - ps[(nl + 1) % 2][nl]);
        }
        /*
        vector<array<ll, 3>> nintervals;
        REP(j, intervals.size()){
            if(intervals[j][1] < nl)
                nintervals.pb(intervals[j]);
        }
        nintervals.pb({nl, nr, nch});
        REP(j, intervals.size()){
            if(intervals[j][0] > nr)
                nintervals.pb(intervals[j]);
        }
        intervals.swap(nintervals);
         */
        intervals.erase(it);
        intervals.insert({nl, nr, nch});
        rev_intervals.erase(it2);
        rev_intervals.insert({nch, nr, nl});
        cout << ans << "\n";
    }
    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 92 / 92